Update wifi header summary text to show metered state

When we detect a network as metered or the user manually overrides
the metered state for a network we should show this in the summary
text for the network. This CL makes it so that this state overrides
the network speed when needed.

Test: robotests
Bug: 68030417
Change-Id: Ia1f3f0a537b6ff711a430466b83664d8f1cad0b6